[tip:perf/urgent] perf/x86: Add support for Intel Xeon-Phi Knights Corner PMU

From: tip-bot for Vince Weaver
Date: Fri Oct 05 2012 - 03:25:07 EST


Commit-ID: e717bf4e4fe8adc519f25c4ff93ee50ed0a36710
Gitweb: http://git.kernel.org/tip/e717bf4e4fe8adc519f25c4ff93ee50ed0a36710
Author: Vince Weaver <vincent.weaver@xxxxxxxxx>
AuthorDate: Wed, 26 Sep 2012 14:12:52 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 4 Oct 2012 13:32:37 +0200

perf/x86: Add support for Intel Xeon-Phi Knights Corner PMU

The following patch adds perf_event support for the Xeon-Phi
PMU, as documented in the "Intel Xeon Phi Coprocessor (codename:
Knights Corner) Performance Monitoring Units" manual.

Even though it is a co-processor, a Phi runs a full Linux
environment and can support performance counters.

This is just barebones support, it does not add support for
interesting new features such as the SPFLT intruction that
allows starting/stopping events without entering the kernel.

The PMU internally is just like that of an original Pentium, but
a "P6-like" MSR interface is provided. The interface is
different enough from a real P6 that it's not easy (or
practical) to re-use the code in perf_event_p6.c

Acked-by: Lawrence F Meadows <lawrence.f.meadows@xxxxxxxxx>
Acked-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Cc: eranian@xxxxxxxxx
Cc: Lawrence F <lawrence.f.meadows@xxxxxxxxx>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1209261405320.8398@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/msr-index.h | 5 +
arch/x86/kernel/cpu/Makefile | 2 +-
arch/x86/kernel/cpu/perf_event.h | 2 +
arch/x86/kernel/cpu/perf_event_intel.c | 2 +
arch/x86/kernel/cpu/perf_event_knc.c | 248 ++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/perfctr-watchdog.c | 4 +
6 files changed, 262 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 957ec87..07f96cb 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -121,6 +121,11 @@
#define MSR_P6_EVNTSEL0 0x00000186
#define MSR_P6_EVNTSEL1 0x00000187

+#define MSR_KNC_PERFCTR0 0x00000020
+#define MSR_KNC_PERFCTR1 0x00000021
+#define MSR_KNC_EVNTSEL0 0x00000028
+#define MSR_KNC_EVNTSEL1 0x00000029
+
/* AMD64 MSRs. Not complete. See the architecture manual for a more
complete list. */

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index d30a6a9..a0e067d 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -32,7 +32,7 @@ obj-$(CONFIG_PERF_EVENTS) += perf_event.o

ifdef CONFIG_PERF_EVENTS
obj-$(CONFIG_CPU_SUP_AMD) += perf_event_amd.o
-obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_p6.o perf_event_p4.o
+obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_p6.o perf_event_knc.o perf_event_p4.o
obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_intel_lbr.o perf_event_intel_ds.o perf_event_intel.o
obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_intel_uncore.o
endif
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 8b6defe..271d257 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -626,6 +626,8 @@ int p4_pmu_init(void);

int p6_pmu_init(void);

+int knc_pmu_init(void);
+
#else /* CONFIG_CPU_SUP_INTEL */

static inline void reserve_ds_buffers(void)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 6bca492..324bb52 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1906,6 +1906,8 @@ __init int intel_pmu_init(void)
switch (boot_cpu_data.x86) {
case 0x6:
return p6_pmu_init();
+ case 0xb:
+ return knc_pmu_init();
case 0xf:
return p4_pmu_init();
}
diff --git a/arch/x86/kernel/cpu/perf_event_knc.c b/arch/x86/kernel/cpu/perf_event_knc.c
new file mode 100644
index 0000000..7c46bfd
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_knc.c
@@ -0,0 +1,248 @@
+/* Driver for Intel Xeon Phi "Knights Corner" PMU */
+
+#include <linux/perf_event.h>
+#include <linux/types.h>
+
+#include "perf_event.h"
+
+static const u64 knc_perfmon_event_map[] =
+{
+ [PERF_COUNT_HW_CPU_CYCLES] = 0x002a,
+ [PERF_COUNT_HW_INSTRUCTIONS] = 0x0016,
+ [PERF_COUNT_HW_CACHE_REFERENCES] = 0x0028,
+ [PERF_COUNT_HW_CACHE_MISSES] = 0x0029,
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x0012,
+ [PERF_COUNT_HW_BRANCH_MISSES] = 0x002b,
+};
+
+static __initconst u64 knc_hw_cache_event_ids
+ [PERF_COUNT_HW_CACHE_MAX]
+ [PERF_COUNT_HW_CACHE_OP_MAX]
+ [PERF_COUNT_HW_CACHE_RESULT_MAX] =
+{
+ [ C(L1D) ] = {
+ [ C(OP_READ) ] = {
+ /* On Xeon Phi event "0" is a valid DATA_READ */
+ /* (L1 Data Cache Reads) Instruction. */
+ /* We code this as ARCH_PERFMON_EVENTSEL_INT as this */
+ /* bit will always be set in x86_pmu_hw_config(). */
+ [ C(RESULT_ACCESS) ] = ARCH_PERFMON_EVENTSEL_INT,
+ /* DATA_READ */
+ [ C(RESULT_MISS) ] = 0x0003, /* DATA_READ_MISS */
+ },
+ [ C(OP_WRITE) ] = {
+ [ C(RESULT_ACCESS) ] = 0x0001, /* DATA_WRITE */
+ [ C(RESULT_MISS) ] = 0x0004, /* DATA_WRITE_MISS */
+ },
+ [ C(OP_PREFETCH) ] = {
+ [ C(RESULT_ACCESS) ] = 0x0011, /* L1_DATA_PF1 */
+ [ C(RESULT_MISS) ] = 0x001c, /* L1_DATA_PF1_MISS */
+ },
+ },
+ [ C(L1I ) ] = {
+ [ C(OP_READ) ] = {
+ [ C(RESULT_ACCESS) ] = 0x000c, /* CODE_READ */
+ [ C(RESULT_MISS) ] = 0x000e, /* CODE_CACHE_MISS */
+ },
+ [ C(OP_WRITE) ] = {
+ [ C(RESULT_ACCESS) ] = -1,
+ [ C(RESULT_MISS) ] = -1,
+ },
+ [ C(OP_PREFETCH) ] = {
+ [ C(RESULT_ACCESS) ] = 0x0,
+ [ C(RESULT_MISS) ] = 0x0,
+ },
+ },
+ [ C(LL ) ] = {
+ [ C(OP_READ) ] = {
+ [ C(RESULT_ACCESS) ] = 0,
+ [ C(RESULT_MISS) ] = 0x10cb, /* L2_READ_MISS */
+ },
+ [ C(OP_WRITE) ] = {
+ [ C(RESULT_ACCESS) ] = 0x10cc, /* L2_WRITE_HIT */
+ [ C(RESULT_MISS) ] = 0,
+ },
+ [ C(OP_PREFETCH) ] = {
+ [ C(RESULT_ACCESS) ] = 0x10fc, /* L2_DATA_PF2 */
+ [ C(RESULT_MISS) ] = 0x10fe, /* L2_DATA_PF2_MISS */
+ },
+ },
+ [ C(DTLB) ] = {
+ [ C(OP_READ) ] = {
+ [ C(RESULT_ACCESS) ] = ARCH_PERFMON_EVENTSEL_INT,
+ /* DATA_READ */
+ /* see note on L1 OP_READ */
+ [ C(RESULT_MISS) ] = 0x0002, /* DATA_PAGE_WALK */
+ },
+ [ C(OP_WRITE) ] = {
+ [ C(RESULT_ACCESS) ] = 0x0001, /* DATA_WRITE */
+ [ C(RESULT_MISS) ] = 0x0002, /* DATA_PAGE_WALK */
+ },
+ [ C(OP_PREFETCH) ] = {
+ [ C(RESULT_ACCESS) ] = 0x0,
+ [ C(RESULT_MISS) ] = 0x0,
+ },
+ },
+ [ C(ITLB) ] = {
+ [ C(OP_READ) ] = {
+ [ C(RESULT_ACCESS) ] = 0x000c, /* CODE_READ */
+ [ C(RESULT_MISS) ] = 0x000d, /* CODE_PAGE_WALK */
+ },
+ [ C(OP_WRITE) ] = {
+ [ C(RESULT_ACCESS) ] = -1,
+ [ C(RESULT_MISS) ] = -1,
+ },
+ [ C(OP_PREFETCH) ] = {
+ [ C(RESULT_ACCESS) ] = -1,
+ [ C(RESULT_MISS) ] = -1,
+ },
+ },
+ [ C(BPU ) ] = {
+ [ C(OP_READ) ] = {
+ [ C(RESULT_ACCESS) ] = 0x0012, /* BRANCHES */
+ [ C(RESULT_MISS) ] = 0x002b, /* BRANCHES_MISPREDICTED */
+ },
+ [ C(OP_WRITE) ] = {
+ [ C(RESULT_ACCESS) ] = -1,
+ [ C(RESULT_MISS) ] = -1,
+ },
+ [ C(OP_PREFETCH) ] = {
+ [ C(RESULT_ACCESS) ] = -1,
+ [ C(RESULT_MISS) ] = -1,
+ },
+ },
+};
+
+
+static u64 knc_pmu_event_map(int hw_event)
+{
+ return knc_perfmon_event_map[hw_event];
+}
+
+static struct event_constraint knc_event_constraints[] =
+{
+ INTEL_EVENT_CONSTRAINT(0xc3, 0x1), /* HWP_L2HIT */
+ INTEL_EVENT_CONSTRAINT(0xc4, 0x1), /* HWP_L2MISS */
+ INTEL_EVENT_CONSTRAINT(0xc8, 0x1), /* L2_READ_HIT_E */
+ INTEL_EVENT_CONSTRAINT(0xc9, 0x1), /* L2_READ_HIT_M */
+ INTEL_EVENT_CONSTRAINT(0xca, 0x1), /* L2_READ_HIT_S */
+ INTEL_EVENT_CONSTRAINT(0xcb, 0x1), /* L2_READ_MISS */
+ INTEL_EVENT_CONSTRAINT(0xcc, 0x1), /* L2_WRITE_HIT */
+ INTEL_EVENT_CONSTRAINT(0xce, 0x1), /* L2_STRONGLY_ORDERED_STREAMING_VSTORES_MISS */
+ INTEL_EVENT_CONSTRAINT(0xcf, 0x1), /* L2_WEAKLY_ORDERED_STREAMING_VSTORE_MISS */
+ INTEL_EVENT_CONSTRAINT(0xd7, 0x1), /* L2_VICTIM_REQ_WITH_DATA */
+ INTEL_EVENT_CONSTRAINT(0xe3, 0x1), /* SNP_HITM_BUNIT */
+ INTEL_EVENT_CONSTRAINT(0xe6, 0x1), /* SNP_HIT_L2 */
+ INTEL_EVENT_CONSTRAINT(0xe7, 0x1), /* SNP_HITM_L2 */
+ INTEL_EVENT_CONSTRAINT(0xf1, 0x1), /* L2_DATA_READ_MISS_CACHE_FILL */
+ INTEL_EVENT_CONSTRAINT(0xf2, 0x1), /* L2_DATA_WRITE_MISS_CACHE_FILL */
+ INTEL_EVENT_CONSTRAINT(0xf6, 0x1), /* L2_DATA_READ_MISS_MEM_FILL */
+ INTEL_EVENT_CONSTRAINT(0xf7, 0x1), /* L2_DATA_WRITE_MISS_MEM_FILL */
+ INTEL_EVENT_CONSTRAINT(0xfc, 0x1), /* L2_DATA_PF2 */
+ INTEL_EVENT_CONSTRAINT(0xfd, 0x1), /* L2_DATA_PF2_DROP */
+ INTEL_EVENT_CONSTRAINT(0xfe, 0x1), /* L2_DATA_PF2_MISS */
+ INTEL_EVENT_CONSTRAINT(0xff, 0x1), /* L2_DATA_HIT_INFLIGHT_PF2 */
+ EVENT_CONSTRAINT_END
+};
+
+#define MSR_KNC_IA32_PERF_GLOBAL_STATUS 0x0000002d
+#define MSR_KNC_IA32_PERF_GLOBAL_OVF_CONTROL 0x0000002e
+#define MSR_KNC_IA32_PERF_GLOBAL_CTRL 0x0000002f
+
+#define KNC_ENABLE_COUNTER0 0x00000001
+#define KNC_ENABLE_COUNTER1 0x00000002
+
+static void knc_pmu_disable_all(void)
+{
+ u64 val;
+
+ rdmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
+ val &= ~(KNC_ENABLE_COUNTER0|KNC_ENABLE_COUNTER1);
+ wrmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
+}
+
+static void knc_pmu_enable_all(int added)
+{
+ u64 val;
+
+ rdmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
+ val |= (KNC_ENABLE_COUNTER0|KNC_ENABLE_COUNTER1);
+ wrmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
+}
+
+static inline void
+knc_pmu_disable_event(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+ u64 val;
+
+ val = hwc->config;
+ if (cpuc->enabled)
+ val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
+
+ (void)wrmsrl_safe(hwc->config_base + hwc->idx, val);
+}
+
+static void knc_pmu_enable_event(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+ u64 val;
+
+ val = hwc->config;
+ if (cpuc->enabled)
+ val |= ARCH_PERFMON_EVENTSEL_ENABLE;
+
+ (void)wrmsrl_safe(hwc->config_base + hwc->idx, val);
+}
+
+PMU_FORMAT_ATTR(event, "config:0-7" );
+PMU_FORMAT_ATTR(umask, "config:8-15" );
+PMU_FORMAT_ATTR(edge, "config:18" );
+PMU_FORMAT_ATTR(inv, "config:23" );
+PMU_FORMAT_ATTR(cmask, "config:24-31" );
+
+static struct attribute *intel_knc_formats_attr[] = {
+ &format_attr_event.attr,
+ &format_attr_umask.attr,
+ &format_attr_edge.attr,
+ &format_attr_inv.attr,
+ &format_attr_cmask.attr,
+ NULL,
+};
+
+static __initconst struct x86_pmu knc_pmu = {
+ .name = "knc",
+ .handle_irq = x86_pmu_handle_irq,
+ .disable_all = knc_pmu_disable_all,
+ .enable_all = knc_pmu_enable_all,
+ .enable = knc_pmu_enable_event,
+ .disable = knc_pmu_disable_event,
+ .hw_config = x86_pmu_hw_config,
+ .schedule_events = x86_schedule_events,
+ .eventsel = MSR_KNC_EVNTSEL0,
+ .perfctr = MSR_KNC_PERFCTR0,
+ .event_map = knc_pmu_event_map,
+ .max_events = ARRAY_SIZE(knc_perfmon_event_map),
+ .apic = 1,
+ .max_period = (1ULL << 31) - 1,
+ .version = 0,
+ .num_counters = 2,
+ /* in theory 40 bits, early silicon is buggy though */
+ .cntval_bits = 32,
+ .cntval_mask = (1ULL << 32) - 1,
+ .get_event_constraints = x86_get_event_constraints,
+ .event_constraints = knc_event_constraints,
+ .format_attrs = intel_knc_formats_attr,
+};
+
+__init int knc_pmu_init(void)
+{
+ x86_pmu = knc_pmu;
+
+ memcpy(hw_cache_event_ids, knc_hw_cache_event_ids,
+ sizeof(hw_cache_event_ids));
+
+ return 0;
+}
diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 966512b..2e8caf0 100644
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/kernel/cpu/perfctr-watchdog.c
@@ -56,6 +56,8 @@ static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
switch (boot_cpu_data.x86) {
case 6:
return msr - MSR_P6_PERFCTR0;
+ case 11:
+ return msr - MSR_KNC_PERFCTR0;
case 15:
return msr - MSR_P4_BPU_PERFCTR0;
}
@@ -82,6 +84,8 @@ static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
switch (boot_cpu_data.x86) {
case 6:
return msr - MSR_P6_EVNTSEL0;
+ case 11:
+ return msr - MSR_KNC_EVNTSEL0;
case 15:
return msr - MSR_P4_BSU_ESCR0;
}
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